Previously, we were NOT actually recomposing Hangul Jamo. We do now.
The two lines in:
test/shaping/texts/in-tree/shaper-default/script-hangul/misc/misc.txt
Now render the same with the UnDotum.ttf font. Previously the second
linle was rendering boxes.
We can also start applying OpenType Jamo features later. At this time,
I have no idea how the 'ljmo', 'vjmo', 'tjmo' features are supposed to
work. Maybe someone can explain them to me?